Infineon Technologies CY8C20647-24LQXI

Overview

CY8C20647-24LQXI from Cypress Semiconductor is a 1.8 V CapSense® controller with SmartSense™ auto-tuning, integrating an M8C 8-bit Harvard-architecture CPU (24 MHz max), 31 capacitive sensing inputs, 6 slider channels, and proximity sensing capability. It delivers 0.1 pF sensitivity, 28 µA/sensor active current (125 ms scan interval), and operates from –40 °C to +85 °C in a 48-pin QFN package.

For engineers reviewing the CY8C20647-24LQXI datasheet, CY8C20647-24LQXI pinout, CY8C20647-24LQXI application, or CY8C20647-24LQXI equivalent, key selection criteria include CSD PLUS™ sigma-delta sensing performance, real-time SmartSense_EMC_PLUS auto-tuning, driven-shield support on five GPIOs, and I²C slave (up to 400 kHz) with hardware address match wake-up.

Technical Context

The device implements a dedicated CapSense analog subsystem with patented CSD PLUS™ algorithm, using internal 1.0 V or 1.2 V reference and configurable CSCLK derived from IMO or external sources. Sensing is performed via charge-transfer sigma-delta modulation with integrated counters and comparator-based threshold detection.

SmartSense_EMC_PLUS operates autonomously during runtime-dynamically adjusting IDAC, scan resolution, and baseline tracking without CPU intervention-to maintain stable signal-to-noise ratio across environmental drift, overlay thickness variation (up to 15 mm glass), and conducted/radiated noise exposure.

Key Specifications

Pinout & Package

48-pin QFN (7 mm × 7 mm, 0.5 mm pitch), thermally enhanced with exposed thermal pad. Pin mapping validated per Cypress Document 001-69257 Rev. *Q, pages 12–13.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar capacitive sensing controller applications.

Compared with MTCH101-I/ST and STM32F072CBT6, CY8C20647-24LQXI provides hardware-optimized capacitive sensing with zero-tuning deployment, lower active power per sensor, and integrated analog resources-making it optimal for high-reliability, production-ready touch interfaces where development time and field robustness are critical.

Availability

CY8C20647-24LQXI is available at Aetrix Electronics and suitable for home appliance control panels, industrial HMI terminals, medical device keypads, and automotive cabin proximity sensors requiring stable component supply and long-term lifecycle support.

Supply support for CY8C20647-24LQXI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Cypress Semiconductor (now part of Infineon Technologies) designs programmable system-on-chip solutions for embedded control, capacitive sensing, and connectivity applications.

CY8C20xx7/S is part of Cypress's CapSense® controller product line, engineered specifically for robust, low-power, production-deployable touch and proximity interfaces in consumer, industrial, and medical equipment.

FAQ

What is the maximum overlay thickness supported by CY8C20647-24LQXI?

The device supports up to 15 mm of glass or 5 mm of plastic overlay thickness, verified using CSD PLUS™ sensing with SmartSense_EMC_PLUS auto-tuning under IEC 61000-4-2/4-3 ESD and EFT test conditions. Performance is maintained without manual recalibration across this range due to real-time baseline and IDAC adjustment.

Does CY8C20647-24LQXI require external components for basic CapSense operation?

No external passive components are required for standard button/slider operation. The device integrates internal IDACs, modulator capacitor switching, and analog reference generation. Only an external 32.768 kHz crystal is optional-for precise sleep timer accuracy-and a single 100 nF VDD bypass capacitor is recommended per layout guidelines.

How does the driven shield feature improve water tolerance?

Driven shield applies a buffered copy of the sensor signal to adjacent traces or ground planes, canceling parasitic capacitance changes caused by water films. Five GPIOs support this mode, enabling guard ring implementation around critical sensors-validated to maintain functionality with ≥1 mm continuous water layer per Cypress application note AN76115.

Can CY8C20647-24LQXI operate from a 3.3 V supply while maintaining 1.8 V CapSense performance?

Yes. The internal LDO regulates analog circuitry-including the CapSense block and reference-to 1.8 V regardless of VDD (1.71–5.5 V). At 3.3 V VDD, the LDO delivers stable 1.8 V analog rail with >60 dB PSRR, ensuring consistent sensitivity and noise immunity without external voltage translation.